On‐the‐fly Catalyst Modification: Strategy to Improve Catalytic Processes Selectivity and Understanding

Abstract

Hydrogenation is a quintessential process to the chemical industry. It is heavily involved in organic synthesis and fuel production, among other processes. Preferentially the reactions are carried out with heterogeneous catalysts and when possible in flow mode. Herein, we provide a retrospective on selective surface modification of catalysts for improved selectivity and understanding of catalytic reactivity. In addition, we provide a prospectus for an emerging strategy of carrying out surface modification on-the-fly to produce novel catalysts in a fast and reproducible way and to understand catalytic phenomena.

Importance of the decoration in shaped cobalt nanoparticles in the acceptor-less secondary alcohol dehydrogenation

“…A p(3x3) cell for (0001) surface and a p(4x4) for (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) surface were considered using a four-layer slab and over 15 Å of vacuum. A dipole correction in the z direction was included.…”

“…17 The catalytic activity vanished once a full surface coverage was reached. However, ligands were also found to have a valuable impact in some cases, especially on reaction selectivity, 18,19,20 a positive influence attributed to steric, 21 orientation, 22 and electronic 23 effects. For example, the ligands density can limit the possible orientations of poly-functional molecules when accessing the catalytic sites.…”

Tuning Nano‐Nickel Catalyst Hydrogenation Aptitude by On‐the‐Fly Zirconium Doping

“…In the past few decades, organic processes conducted under flow conditions have attracted growing attention due to significant benefits in respect to environmental compatibility, safety and efficiency . In particular, chemoselective flow heterogeneous catalysis yields desired products without significant levels of by‐product, avoiding costly, unsustainable and time‐consuming purification processes.…”

Boosting the Performance of Nano-Ni Catalysts by Palladium Doping in Flow Hydrogenation of Sulcatone

“…It is not surprising that flow catalytic hydrogenation has received renewed interest by industry and academia in the last decade [40]. Continuous flow processes in micro-reactors enable savings in chemicals (reagents and solvents) and energy consumption, reduce reaction times, improve mass transfer and process safety, simplify workflows and reaction schemes, increasing control and quality of the entire process [41]. However, continuous high-pressure flow processes require innovative solutions concerning active metal morphology, catalyst support, and reactors [42,43].…”

“…This type of reactor paved the way for the development of novel heterogeneous hydrogenation processes that comply with the green chemistry exigencies and sustainable goals. In our research group, we have used the system not only to test the catalysts catalytic proficiencies but to modify them, using a technique called on-the-fly modification in which we can modify the surface with other metals via a chemical reduction of organometallic complexes and metal salts [32,41,45,46]. With respect to support, they need to have suitable nominal sizes and swelling properties that enable high-pressure flow processes.…”